The standard rationality hypothesis implies that individual behaviour can be represented as the maximization of a suitably restricted utility function. This hypothesis lies at the heart of a large body of economics, of course, but also in political science, ethics, and other major branches of the social sciences. Though this hypothesis of utility maximization deserves our continued respect, finding further refinements and developing new critiques remain areas of active research. The main purpose of the Handbook of Utility Theory is to make more widely available some recent developments in the area. The editors selected a list of topics that seemed ripe enough to be covered by review articles. Then they invited contributions from researchers whose expert work had come to their attention. So the list of topics and contributors is largely the editors’ responsibility. Each contributor’s chapter has been refereed, and revised according to the referees’ remarks. Whereas Volume I of the Handbook of Utility Theory is largely concentrated on basic theory, the present volume is concerned with extensions and applications to other branches of economic theory. Taken together, these first two vo